Electric alarm device



Oct. '28, 1930.

i UNM/0 E. E. scoTT ET AL 1,779,987

ELECTRIC -ALARM DEVICE Filed Jan. 31A. 1928 5 Sheets-Sheet l 3 ,m l i l, /f ff/ if Je tow 47 ff ff f 57716152 7, SMU,

gime?" M'dendug/z,

Oct. 28, 1930.

E. E. scoT-r ET AL v 1,779,987

ELECTRIC ALARM DEVICE Filed Jan. 3l, 1928 5 Sheets-Sheet 2 CL 28, 1.930. E, E, SCQTT ET AL 1,779,987

. ELECTRIC ALARM DEVICE F'ild Jan. 3l, 1928 3 Sheets-Sheet 3 Patented Oct. 28, 1930 UNITED STATES PATENT OFFICE ERNEST E. SCOTT AND1 ELMER `I-I. BRIDENBAGH, OF DENVER, COLORADO, ASSIGNORS TO THE ELECTRIC ALARM CO., INC., 0F DENVER, COLORADO, A CORPORATION OF COLORADO ELECTRIC ALARM DEVICE Application filed January 31, 19:28.

This invention relates to improvements in automatic elect-ric alarms and has reference more particularly to an' alarm mechanism which can be applied to automobiles and which will automatically sound the horn whenever the automobile is disturbed.

It frequently happens that when automobiles areparked along the street, unauthor` ized persons will approach the automobile and remove tires or accessories and will even steal the automobile itself. Even if an automobile is locked it sometimes happensr that thieves will tow the automobile away to some secluded place where the lock can be removed and the automobile operated by its own power.

It is the further object of this invention to produce an automatic electric signal that will be adapted for universal application and which can be applied to houses, garages, storcs and any other building` where a signal is desirable for the purpose of sounding an alarm in case unauthorized people attempt to enter the building.

The above and other yobjects which will become apparent as the description proceeds are attained by means of an apparatus which,

riely described, comprises a pendulum mounted for vibration on a horizontal axis and which is held in substantially horizontal posit-ion by means of a spring. T.When the support to which this pendulum is secured is vibrated in an up and down direction, the pendulum will close an electric contact which serves to energize an electromagnet which attracts an armature that is provided with means for closing the electric circuit so that the magnet will remain energized after the contacts associated wit-h the pendulum have been separated. The electromagnet is provided with an interrupter which makes it vibrate and which rotates a contact member by means of a step by step mechanism. The magnet will continue to operate until the circuit is again broken by the step by step mechanism. Means is associated with the electromagnet for opening and closing a signal ci l'cuit during the operation of the magnet and therefore whenever the apparat-us is set in motion, it will 'continue to sound an alarm Serial N0. 250,780.

at frequent intervals tor a predetermined length of time. lT-fhen this device is attached to an automobile, the alarm is constituted by the horn ot the automobile and is operated from the ignition battery. l

Having now briefly described our invention, we will proceed to describe the same in detail and reference for this purpose will be had to the accompanying drawings in which:

Fig. l is a side elevation of the mechanism showing the saine located in a box or casing from which the cover has been removed;

Fig. 2 is a trans f'erse section taken on line 2 2, Fig. l;

Fig. 3 is a vertical transverse section taken on line 3 3, Fig. l;

a is an elevation of a fragment of the device showing the parts to a. somewhat larger scale and in which some of the parts are shown as sections taken on line 4 4, F ig. 3;

Fig. 5 is a section taken on line 5 5, Fig. l;

Fig. G is a section taken on line 6 6, Fig. 3, and shows the construction of the dashpot;

Fig. 7 is a section taken on lines 7 7,

S is a view showing the rear side ofthe insulating base plate and has been taken along line 8 8, Fig. 3; and

Fig. 9 is a diagrammatic representation of the electrical connections and shows the principal parts of the device in a more or less diagrammatic manner.

ln the drawing numeral 1 represents a box or casing, one side of which is open and which is provided with brackets or feet 2 by means of which it may be secured to a suitable part of an automobile or to any other object with which it is to be associated. The casing is provided with a removable cover 3 which may be held in place by any suitable means. That side orp the boX which has been indicated by reference numeral 4 and which lies between the two brackets 2 is .provided with tour holes through which the contacts A, B, C and D extend. These contacts have been illustrated in Figs. 5 and 7 and consist of a bolt 5 that is provided at one end with a nut 6 and which extends through the openings in side 4. The head of the bolt and the nut are separated from the metal parts by means of insulating washers 7. A screw 8 serves as a means for clamping an electrical terminal 9 in place. Secured to the inner end of these contacts are springs 10, which are clamped between the head of the bolt and the inner washer 7 in the manner shown in Fig. 7. The mechanism comprising this alarm is all secured to an insulating plate 11, which is of the proper size `to fit the inside of the box and which is separated from the inner surface of the bottom by means of a sheet of insulating material 12, which has been shown in Figures 2 and 3. Y insulating plate 11 is of substantially rectangular shape and has` a notch 13 on one side and another notch 14 removed from one corner. It is also provided with projections 15 which are adapted to lit against the sides of the casing in thefmanner shown in Fig.1. On its rear surface the plate has a iange 16 that extends around three sides thereof and which serves toV engage the insulating sheet 12.

The flange 16 serves to space the lower sur- ,I face of plate 11 away from the inner surface of the insulating sheet 12 so as to provide room for a number ofelectrical connectors which have been shown in Fig. 8 and which will hereinafter be more particularly identified. Secured to the upper surface of plate 11 are the operating parts which will now be identified. Numeral 17 represents a` solenoid which is held in place by means of a strap 18 whose ends are secured to the plate by means of a screw 19. An electromagnetic core 20 extends into the opening in the solenoid in the manner indicated in Fig. 1. The lower end of this core is provided with a section of reduced diameter which has been designated by reference numeral 21 and at each end of this section circular flanges 22 have been provided in the manner shown. A cylindrical part of the Vcorewhich has been designated by numeral 23 rextends belowthe lowermost flange 22 and serves as a stop which engages the inner surface of the casing and therefore limits the movement of the solenoid in one direction. An arm 24 is pivoted at one end to a pivot pin 25, which is secured to the insulating base plate 11. The other end ofthisarm'is provided with an offset portion 26 that projectsin between the flanges 22 in the manner shown in Figs. 1 and 9. A pawl A27 is pivotally se cured to arm 24 at 28 and is urged' in a clockwisedirection'by means of a spring 28': `A ratchet wheel 29 is mounted for rotation about a pivot` 30, and' is'provided on its periphery with a number of ratchet teeth 31, which are engaged by a downwardly ex.- tendlng portion 32 of the pawl 27 Whenever the electromagnet is energized to such4 an extent that the core 20 is caused to move upwardly into the solenoid,VV arm 24Vwi'll be rotatedabout its pivot and this will carry' the pivot point 28 upwardly, thereby moving pawl 27 upwardly so as to cause the part 32 to engage with one ofthe ratchet teeth and rotate the ratchet wheel about its pivot in a clockwise direction. It is apparent that every time that the core 2O is moved upwardly, it will impart corresponding rotary motion to the ratchet wheel.

Secured to the plate 11 by means of screws -33 is a bracket 34 ofconducting material.

This bracket has anoutwardly extending portion 35 which terminates in a part 36 that is parallel to the main portion ofthe bracket in the manner shown in Fig. 2. A pivot 37 extends between'the part 34 and the partv 36 and is provided with conical ends 38. ,One of these conical ends extends into an opening in the part 34 and the other intoan opening in the inner end of the adjusting screw39. An arm 40 is secured tothe pin 37 at a point substantially midway between its ends. This arm has a downwardly extending portion 41 that is provided with a notch 42 to which one end of the spring 43 is connected in the manner shown in Figs. 1 and 2. The'. other end of this spring is secured to the upwardly extending portion 44 of an L-shaped bracket member whose other end 45 extends through an opening formed between the upper surface of the plate 11 and the offset part 46 of the bracket member 34. A rod 47 has one endsecured to the vertical part 44 and has its other end provided with `threads 48. A

nut 49 is connected with the threaded poi`-` Y tion 48 and extends through an opening nik the side ofthe casing in the manner shown in Figs. land 2. The inner end of this nut has a flange 50 that acts as a stop which prevents the nut from moving outwardly. The

lil() tension of spring 43 produces'a force tending to move the bracket 44V towards the left in Fig. 2, but this movement is resisted by the flange 50 of the nut 49. By rotating the nut it is evident that the position of bracket 44 canbe altered and in this way the tension of the spring 43 can be adjusted'to whatever extent is desired. Secured to the free end of arm 40 is a weight 51. This weight may be formed of lead or any other metal and is provided on its upper surface with a plug 52 of rubber or other suitable material which is adapted to engage the inner side of the casing in the manner shown in Fig. 1. Arm

42 is provided with a flat portion 53 which is bent at right angles to the plane of the armv in the mannerjmost clearly shown in Fig. 2. An electric contact 54 of platinum, tungsten or Vother highly refractory conducting material is secured to the part 53 and serves to engage a similar contact 54a that is carried by the vertical arm 55 of an L-shaped contact whose other arm 56 rests on the 'upper surface of plate 11 yand is secured to vthe lat- Y ter byl meansl of a Vscrew 57. kSecured to the ratchet wheel "29 is Va Vring 58 formed yfrom Vco a strip of conducting material. This ring is secured concentrically to the ratchet wheel 29 and has an inwardly o'set portion 59 at one point in its periphery, Figs. 4 and 9. The bracket member 34 hasl a downwardly extending portion Whose lower end 6l is at an angle to the part 60. A screw 62 serves to secure the parts 60 and 6l to the plate ll in the Vmanner shown. The lower end 63 of part 6l is bent upwardly so as to extend at right angles to the plane of parts 60 and 6l. A contact member 64 has one end secured to the part 63 by means of rivets. This contactmember has its free end 65 bent substantially at right angles and extending inwardly towards the outer surface of ring 58 4). This contact member is so adjusted that when the parts are in the posit-ion shown in Fig. 4, the end 65 will not contact with the ring 58, but if the ring is rotated a short distance, the end 55 will come into contact with it so as to close an electric circuit. The function performed by contact 64 will be more fully explained hereinafter.

Secured to the rear surface of the insulating plate 15 is an electrical conductor 66, one end of which is electrically connected with the screw 62 and the other end of which is secured to the plate by means of a screw 67. This contact has its extreme end 68 bent upwardly along the edge of plate l1 in the mannery shown in Fig. 7 and is adapted to come in contact with the inner end of the flexible contact member 10 in the manner shown. Another contact strip which is formed from two angularly joined parts 69 and 70 has one end electrically connected to the bracket 55 by means of the screw 57. The two ends of the portion 7 0 are electrically connected with screws 71 and 72 and therefore whenever the contacts 54 and 54ZL are brought into electrical contact an electrical connection is established between screws 57, 7l and 72. Secured to screw 7l is the end 73 of t-he magnet coil winding and the other end of this winding, which has been designated by numeral 74, is soldered to the casing or otherwise electrically connected therewith.

Secured to the plate ll by means of the screw 72 is an L-shaped contact having a vertically extending' portion 75. This portion carries a contact 76 which is adapted to cooperate with a similar contact 76a carried on the end of the spring arm 77. This arm has its other end securedto the arm 24 by means of a rivet 78, that secures it to the upstanding lug 79. Vfhen the core 2O is in its lowermost position, (Fig. l) contacts 76 and 76a will be brought together so that current may iiow from the screw 72 to the arm 24. An electrical connector 80 extends from the pivot pin 30 to the pivot pin 25 so as to electrically connect these parts.Y

Battery 81, Fig. 9, is connected to the terminal A by means of a Wire 82 in which a small electric switch 83 is interposed. One terminal of this battery is grounded at 84, and the casing l is grounded at 85.

Let us now assume that the pendulum is vibrated to such an ext-ent that contact 54 encontact 54a. If we now refer to Fig. 9, we will find that an electrical connection has been established which permits current to flow from the battery through the connector 66 and through parts 60 and 34 to the arm 40 and from thence through the connector 69 to the end 73 of the magnet coil and after passing through the magnet winding will return to the battery through ground. This energizes the magnet which then attracts the core 20 and rotates the arm 24 about its pivot 25. When the arm moves upwardly, the ratchetwheel 29 is moved about its pivot and the end 65 of the contact spring 64 is brought into engagement with the outer surface of ring 58. lVhen contacts 54 and 54a separate, the current can flow through the contact 64 into the ratchet wheel 29 and through the radial spokes of this wheel to the pivot pin 30 and thence through connector 8O to pivot pin 25. From here it will pass through the contact member 77 and from contacts 7 6a to 76 and thence through connectors to the coil of the electromagnet. The electromagnet will therefore be again energized and will raise the core 20, thereby moving the ratchet wheel another step and breaking connection between contacts 76 and 7 6a. Contact 76 and 76a and the arm 24 form a circuit interrupter which alternately makes and breaks the circuit to the electromagnet and the latter will therefore be periodically energized until wheel 29 has been rotated three hundred sixty degrees when the current will break for the reason that contact point 65 will then register with the notch 59. The parts will remain stationery until connection is again established between contacts 54 and 54a when the cycle will be repeated. Arm 24 is provided with an extension 86 which carries a roller 87. Secured to the base plate ll by means of a screw 88 is a contact member 90, which is provided with a vertical arm 91 to which one end of the spring 92 is secured by means of a rivet 93. The free end of this spring carries a contact point 94 which is so located that it can be brought into electrical contact with the corresponding contact point 94a that is carried by the bracket member 95. An electric connector 96 extends from the bracket 95 to a point adjacent the spring contact l0 of the terminal B. It will be apparent that whenever the core 20 is moved upwardly and the arm 24 rotated in a clockwise direction about pivot 25, the y spring 92 downwardly until the contact points 94 and 94a make electrical connection. Current will then flow from the terminal B through the connector 96 to bracket 95 and thence through roller 87 will move the r' spring 92 to terminal D from A, muy rightV in a clockwise which it will pass by way of the wire 97 to the horn 98, which is grounded at 99, therefore whenever the core is in its uppermost position, a circuit is closed to the horn which will therefore be sounded. This circuit is broken whenever the core is in its lowermost position and it will therefore be apparent that as long as the core 20 is vibrating, the horn will be intermittently sounded. Whenever the parts 65 and 59 assume the position shown in Fig. 9, the circuit will be broken andthe parts will then remain stationary until the two contacts 54 and 54EL are again brought together. Y

It is apparent that if the adjustment of the pendulum is very sensitive the contacts 54 and 54a may be in position to establish an electric current at the moment when the notch 59 assumes the position shown in Fig. 9 and if this should happen, the parts would be caused to operateuntil the ratchet wheel 29 has made another revolution. In order to' prevent this from occurring accidentally, means is provided for holding the pendulum against vibration for a short time after the ratchet wheel 29 has completed its revolution. This means comprises an arm 100vwhich is pivoted at 101. One end of this arm has an upwardly extending portion 102 to which oneend of the spring 103 is secured in the manner shown in Fig. 1. The free end of this spring extends underneath plug 104 that is carried by the weight 51. The pivot 101 is carried by a bracket 105, which has beenillustrated in Fig. 4. One end of this bracket is bent downwardly so as to rest upon the upper surface ofplate 11 and is secured to the latter by means of a screw 106. This bracket has an arm 107 that extends downwardly at substanangles and is provided with an opening forthe reception of the pivot to which it is secured by means of a cotter pin 108. On the other side of this pivot pin an arm 109 extends diagonally and terminates in an outwardly extending portion 110 to which the dashpot cylinder 111 is secured by means of a nut 112. Bracket 105 has an extension 113 Vwhich terminates below the pivot pin 101and carries a pin 114 to which one end of spring 115 is anchored. VThe other end of this spring is connected to the lever 100 at 116. Asthe line of force exerted by the spring 115 passes below the pivot 101, it produces a torque tending to rotate the lever 100 direction. The free end of this lever is connected by means of a pivot 117 to the upper end of a rod 118 whose lower end carries a piston 119 that cooperates with the dashpot in order to obtain a retarding eifect for the purpose whichV will hereinafter be fully described. Secured to the spokes 120 of the sprocket wheel 29 is a cam 121.v This cam is spiral shapedl and extends substantially one complete revolution. The ends of this cam are connectedby a straight:portionV122.v -Lever100 carries'a downwardly extending part 123 which is held in contact with the outer surface of the cam by the action of spring 115. It is now apparent that as the ratchet wheel is rotated in a clockwise direction, the cam V121 will slowly move the arm 100 upwardly against the tension of the spring 115. This will bring the freeend'of spring 103 into contact with the lower end of plug 104 and keep the weight 51 from vibrating. The tension of spring 103 will beV gradually increased until the part 123 arrives at' the end of the cam when a further motion of wheel 29 Vwill remove the cam surface so asto permit the spring 115 to return the parts to the position shown in Fig. 1. The action of the spring'in returning .lever v100 is resisted by the action of the y dashpot and as the cam 121 ceases functioning a short time before the notch 59 arrives beneath the contactpoint the pendulum will be held against vibration for a short time by the retarding action of the dashpot. This assures that the parts will not start operating again until the device is subj ected to an undue amount of vibration. This retarding action is consideredto be of con- Y siderable importance as with the delicatel adjustments usually provided, it sometimes happens that the pendulum will be vibrated suciently to bring contacts 54 and 54a, together on account ofthe vibrations'due to the operation of the parts as described. Vhen the cam 121 and dashpot 111 are provided, however, this contingency cannot occur. After the parts have returned to the position shown in Fig'. 1, the pendulum is then free to vibrate and to start the mechanism operating whenever the vibrations become sufficiently severe to vmake connection between contacts 54 and 54a. The sensitiveness of the adjustment can be regulated by the simple expedient of rotating the nut'49. Y 7

Attention is called to the fact that terminals A and B have been connected by means of a strap 124. Y

It is evident that itis possible to employ as many separate pendulum contact makers inV parallel las may be desired'and in Fig.v 9 we have shown a separate assembly comprising parts 40a, 51a, 43a, 54 and 54a. Contacts 54`and 54a are connected by vconductorsvrzva and y. 1t is obvious that` such assemblies can be located at any distance from the other apparatus and that these auxiliary assemblies can Vbe attached to doors, windows, safes or in fact to any article that is liable to be disturbed. One use of such auxiliary assemblies is at railwayk crossings where they maybe attached to the tracks on each` side and willl cause the signal to operate on the ,approach of va train. This device is adapted for a large number of uses of which those referred to are examples only.

Since the rate of Yvibration lof the electromagnet is quite constant andas the signal operates in synchronism the signals will be distinctive as a given number will be made each time the device is operated.

Having described the invention what is claimed as new is:

l. A theft alarm device comprising, in combination, a signal circuit including a switch for the control of the sivnal, an electromagnetic device for actuating the signal control switch, said device comprising a movable armature, a control switch for the electromagnetic device, means operated by the armature for intermittently operating the signal control switch, a time limit cut off switch for interruptingl the current to the electromagnetic device, means comprising a step by step mechanism for actuating the time limit cut off switch when the armature moves, a normally open theft protective switch connected in shunt with the time limit cut off switch, and neans operated by the step by step mechanism for holding the theft protective switch in open position when the time limit cut off switch is in circuit closing position and until it has returned to circuit opening position.

2. A theft alarm device comprising, in combination, a signal circuit including a switch for the control of the signal, an electromagnetic device for actuating the signal control switch, said device comprising a movable armature, a control switch for the electromagnetic device, means operated by the armature for intermittently operating the magnet control switch and the signal control switch, a time limit cut off switch for interrupting the current to the electromagnetic device, means comprising a step by step mechanism for actuating' the time limit cut ott switch when the armature moves, a theft protective switch connected in shunt with the time limit cut off switch, said last named switch comprising two relatively movable, normally spaced contacts, one of which has a greater amount of inertia than the other, and means operated bythe step by step mechanism for retaining the theft protective switch in open position while the time limit cut off mechanism is operative.

3. A theft alarm device comprising, in combination, a signal circuit including a switch for the control of the signal, an electromagnetic device for actuating the signal control switch, said device comprising a movable armature, al control switch for the electromagnetic device, means operated by the armature for intermittently operating the magnet control switch and the signal control switch, a time limit cut olf switch for interrupting the current to the electromagnetic device, means comprising a step by step mechanism for actuating the time limit cut olf switch when the armature moves, a theft protective switch connected in shunt with the time limit cut off mechanism, said last named switch comprising two relatively movable, normally spaced contacts, one of which has a greater amount of inertia than the other, means controlled by the step by step mechanism for retaining the theft protective switch in open position, while the time limit cut oil' mechanism is operative, and a retarding device connected with the theft protective switch for retaining it in open position for a short period of time after the cut off switch has returned to inoperative position.

4,. A theft alarm device comprising', in combination, a signal circuit including a switch for the control of the signal, an electromagnetic device for actuating the signal controlswitch, said device comprising a movable armature, a control switch for the electromagnetic device, means operated by the armature for intermittently operating the signal control switch, a. time limit cut olf switch for interrupting the current to the electromagnetic device, means comprising a step by step mechanism for actuating the time limit cut o5 switch when the armature moves, a normally open theft protective switch connected in shunt with the time limit cut olf switch, a cam mounted for rotation, means comprising the step by step mechanism for rotating the cam when the time limit cut off switch is in circuit closing position, and means operated by the cam for holding the theft protective switch in open position during the time that the time limit cut oil switch remains in circuit closing position and until after the time limit cut off switch has returned to open position.

' 5. A signal control mechanism comprising,

in combination, a source of electric energy, an electromagnct, an electric circuit extending from the electromagnet to one terminal of the electric source, said circuit having a. portion thereof formed by two parallel paths, one of said paths having a, normally open theft protective swit h interposed therein and the other of which has a normally open time limit circuit closer and a normally closed circuit interrupter in series, an armature associated with the electromagnet, means associated with the armature for opening the circuit interrupter when the armature is in attracted position and for allowing the interruptor contacts to be brought into circuit closing position when the armature is released hy the magnet, a step by step mechanism operated by the armature for controlling the time limit circuit closer, and means controlled by the step by step mechanism for holding the theft protective switch in open position during the time limit circuit closer is in circuit closing position ant for releasing the theft protective switch when the time limit circuit closer has returned to open position.

6. A signal control mechanism comprising, in combination, a terminal adapted to be connected with one pole of a source electrical lili) energy, an electromagnet, a conductor Vezitending from the terminal to theelectromagnet, a lnormally open time limit circuit closer anda normally closed circuit interrupting switch interposed in series in the conductor, a shunt about the time limit circuit closer and the circuit interrupter, a normally open theft protective switch in the shunt, an armature associated with the electromagnet,means associated With the armature for opening the circuit interrupter when the armature moves Y.

the'renergization of the elec'- in response to for again closing the intertroinagnet and rupter contacts been deenergized, means including a step by step mechanism Voperated bythe movementl of the armature for operating the time limit Vcircuit closer and means operated by the step by step mechanism for holding the theft pro= tective switch in open position While the time limit circuitv closer is in closed position. p

`7. A signal control mechanism comprising, in combination, a terminal adapted to be connected with oneV pole of a source of electric energy, an electromagnet, a conductor eX- tending from the terminal to the electromagnet, a normally open time limit circuit closer and a normally closed circuit interrupting vswitch interposed in seriesv in the conductor, a shunt about the ,circuit closer and the circuit interrupter, a normally; open theft protective switch in the shunt, an armature associated with the electromagnet, means associated With the cuit interrupter responseltoy the energization of the electro magnet and for again closing the interruptei armaturefor opening the cir.-

contacts after the electromagnet has been dee i energized, means including a step by step mechanism operated by the movement of the armature for operating the time limit circuit closer, means operated by the l,stepV by step mechanismV for holding the theft protective switch in open position While tlietime limit circuit closer is in closedposition, and a ree tardiiigdevice for holding the theft protective switch-open for ashoit period of time after the time limit circuit closer has been returned to openy position.

In' testimonypwhereof WeA affix our signa- Y,

Y iiiuvii'sirii.` soofrfr. i

ELMER ii. ifiiainiiivisAuen.l

tures.

after the 'electromagnet has when the armature moves in 

